Species composition of the biospere
- Intricate webs of interacting organisms
- 2,000,000 species are known
- 18,000 plants & animals discovered per year
- estimated 87% of Eukaryotas unknown
- Reflects billions of ways organisms have adapted, over and over, to a changing planet
- Humans have altered 75% of ice-free surface
- alters species composition
“Lines of the geography of plants” by Humboldt, 1817
Species are spatially arranged
Species are spatially arranged
Similar biological communities reside within our biomes
Climate drives broad distribution of terrestrial biomes
Biomes have distinct soil types
Species distribution varies within biomes
Seasons can impact species distribution
Migration can cross many biomes: Birds
Species may also be adapted for seasonal habitats
Niches define the limiting factors for a species
Tolerance Range: Coral Reefs
Ecological niches exist in n-dimensions
Distribution within biological communities
Species distributions are related to their niche space
Niches often overlap for different species
Ranges versus distribution: Crocodile
Ranges versus distribution: Plants
Species distributions: Coconut tree
Biogeography and species ranges: Alfred Wallace 1859
Zoogeographic regions: Wallace
Global change: climate refugia (Polar bear)
Global change: Range shifts of plants
